Back to EveryPatent.com
| United States Patent |
5,190,989
|
|
Himori
|
March 2, 1993
|
Hydrophilic group-containing AB-type block copolymer
Abstract
An AB-type block copolymer represented by formula (I):
##STR1##
wherein R.sup.1 represents a hydrocarbon group having 1 to 10 carbon
atoms; R.sup.2 represents a hydrogen atom or a hydrocarbon group having 1
to 10 carbon atoms; R.sup.3 represents a benzyl group,
##STR2##
wherein R.sup.4 represents an alkyl group having 1 to 10 carbon atoms, or
an alkyl group having 1 to 18 carbon atoms; M represents a group
represented by the formula (M.sup.2).sub.m --(M.sup.1).sub.n or
(M.sup.1).sub.m --(M.sup.2).sub.n, each of m and n being a natural number
of 20 to 5000; is prepared by a process of first polymerizing either a
monomer for forming the M.sup.1 block or a monomer for forming the M.sup.2
block in the presence of a sulfur-containing compound having formula
(XIII):
##STR3##
wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above so as to
synthesize a polymer initiator having a dithiocarbamate group as indicated
in formula (XIII) at the polymer terminal end, and then polymerizing the
other monomer in the presence of the polymer initiator obtained in the
first step; wherein the polymerization reactions in the first step and in
the second step are carried out upon exposure of the monomers to
ultraviolet radiation.
| Inventors:
|
Himori; Shunichi (Yokkaichi, JP)
|
| Assignee:
|
Mitsubishi Petrochemical Company Limited (Tokyo, JP)
|
| Appl. No.:
|
620389 |
| Filed:
|
November 30, 1990 |
Foreign Application Priority Data
| Jun 23, 1987[JP] | 62-154458 |
| Current U.S. Class: |
522/57; 522/176; 522/182; 525/267; 525/301 |
| Intern'l Class: |
C08F 002/50; C08F 004/00; C08F 293/00 |
| Field of Search: |
522/57,176,182
525/267,301
|
References Cited
U.S. Patent Documents
| 3287298 | Nov., 1966 | D'Alelio | 525/294.
|
| 4429076 | Jan., 1984 | Saito et al. | 525/301.
|
| 4604425 | Aug., 1986 | Ohmura et al. | 525/88.
|
Other References
T. Otsu & A. Kuriyama; Living Radical Polymerization in Homogeneous System
by Using Iniferter; J. Macromol. Sci.-Chem., A21 (8 & 9), pp. 961-977
(1984).
Polymer Bulletin, vol. 7, 1982, pp. 197-203, Springer-Verlag; T. Otsu et
al; "Efficient Synthesis of Two or Multi Component Block Copolymers
Through Living Radical Polymerization with Polymeric Photoiniferters".
Database Chemical Abstracts, (Host STN), 1985, No. 102(2):167246w,
Columbus, Ohio, U.S.; T. Otsu et al: "Polymer Design by Iniferter
Technique in Radical Polymerization: Synthesis of AB and ABA Block
Copolymers Containing Random and Alternating Copolymer Sequences".
Polymer Bulletin, vol. 11, 1984, pp. 135-142, Springer-Verlag; T. Otsu et
al "Living Mono- and Biradical Polymerizations in Homogeneous System
Synthesis of AB and ABA Type Block Copolymers."
|
Primary Examiner: McCamish; Marion E.
Assistant Examiner: Berman; Susan
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt
Parent Case Text
This application is a continuation of application Ser. No. 209,587, filed
on Jun. 22, 1988, now abandoned.
Claims
What is claimed is:
1. An AB-type block copolymer represented by formula (I):
##STR42##
wherein R.sup.1 represents a hydrocarbon group having 1 to 10 carbon
atoms; R.sup.2 represents a hydrogen atom or a hydrocarbon group having 1
to 10 carbon atoms; R.sup.3 represents a benzyl group,
##STR43##
wherein R.sup.4 represents an alkyl group having 1 to 10 carbon atoms, or
an alkyl group having 1 to 18 carbon atoms; M represents a group
represented by the formula (M.sup.2).sub.m -(M.sup.1).sub.n or
(M.sup.1).sub.m -(M.sup.2).sub.n, each of m and n being a natural number
of 20 to 5,000; M.sup.1 represents a (meth)acrylate residue represented by
the formula:
##STR44##
wherein R.sup.5 represents a hydrogen atom or a methyl group, and R.sup.6
represents a hydrocarbon group having 1 to 18 carbon atoms, or an aromatic
vinyl residue represented by the formula:
##STR45##
wherein R.sup.7 represents a hydrogen atom or a methyl group, R.sup.8
represents a phenyl group, a halogenated phenyl group or an alkylphenyl
group or a fatty acid vinyl ester residue represented by the formula:
##STR46##
wherein R.sup.9 represents a hydrocarbon group having 1 to 18 carbon
atoms, M.sup.2 represents a hydrophilic group-containing vinyl residue
represented by any one of the formulae (II) to (XII):
##STR47##
wherein R.sup.10, R.sup.11 each represent a hydrogen atom, a methyl or a
hydroxyl group, and Z represents a hydrogen atom, an alkali metal atom,
ammonium or an organic amine;
##STR48##
wherein R.sup.10 and Z have the same meanings as in the formula (II), and
R.sup.12 represents an alkylene group having 1 to 10 carbon atoms;
##STR49##
wherein R.sup.10, R.sup.11 and Z have the same meanings as in the formula
(II), and R.sup.12 has the same meaning as in the formula (III):
##STR50##
wherein R.sup.10 and R.sup.11 have the same meanings as in the formula
(II), R.sup.13 and R.sup.14 each represent a hydrogen atom, an alkyl group
having 1 to 10 carbon atoms or a sulfonated alkyl group represented by the
formula --R.sup.12 SO.sub.3 Z, wherein R.sup.12 and Z have the same
meanings as in the formula (III):
##STR51##
wherein R.sup.10, R.sup.11 and R.sup.12 have the same meanings as in the
formula (IV), and R.sup.13 and R.sup.14 have the same meanings as in the
formula (V):
##STR52##
wherein R.sup.10, R.sup.11, R.sup.12, R.sup.13 and R.sup.14 have the same
meanings as in the formula (VI), and R.sup.15 represent a hydrogen atom,
an alkyl group having 1 to 10 carbon atoms or a sulfonated alkyl group
represented by the formula --R.sup.12 SO.sub.3 Z, wherein R.sup.12 and Z
have the same meanings as in the formula (III):
##STR53##
wherein R.sup.16 represents a hydroxylated alkyl group having 1 to 18
carbon atoms and having at least one hydroxyl group, and R.sup.10 and
R.sup.11 have the same meanings as in the formula (II):
##STR54##
wherein R.sup.10 and R.sup.11 have the same meanings as in the formula
(II), and R.sup.17 represents a polyethylene glycol group or a
polypropylene glycol group represented by the formula:
##STR55##
wherein l represents a natural number of 1 to 10 and X represents an alkyl
group having 1 to 10 carbon atoms or Z, --PO.sub.3 H.sub.2, --PO.sub.3 HZ
or --PO.sub.3 Z.sub.2, wherein Z has the same meaning as in the formula
(II)
##STR56##
wherein R.sup.10 and Z have the same meanings as in formula (II):
##STR57##
wherein R.sup.10 has the same meaning as in formula (II); or
##STR58##
wherein R.sup.10, R.sup.11 and Z have the same meanings as in formula
(II); and M.sup.2 further represents a vinylpyrrolidone residue or an
ammonium salt of the formula (V), (VI) or (VII), prepared by a process,
comprising:
a first step of polymerizing either a monomer for forming the M.sup.1 block
or a monomer for forming the M.sup.2 block in the presence of a
sulfur-containing compound having formula (XIII):
##STR59##
wherein R.sup.1, R.sup.2 and R.sup.3 are as defined above so as to
synthesize a polymer initiator having a dithiocarbamate group as indicated
in formula (XIII) at the polymer terminal end; and
a second step of polymerizing the other monomer in the presence of the
polymer initiator obtained in the first step; wherein the polymerization
reactions in the first step and in the second step are carried out upon
exposure to ultraviolet radiation.
2. The block copolymer according to claim 1, wherein the residue M.sup.1 is
formed from a (meth)acrylate monomer selected from the group consisting of
methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate,
isobutyl (meth)acrylate, hexyl (meth)acrylate, isooctyl (meth)acrylate,
2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate
and stearyl (meth)acrylate.
3. The block copolymer according to claim 1, wherein the residue M.sup.2 is
represented by the formula (II) and formed from a hydrophilic
group-containing vinyl monomer selected from the group consisting of
(meth)acrylic acid, crotonic acid, sodium (meth)acrylate, potassium
crotonate, ammonium (meth)acrylate,
##STR60##
4. A polymer composition comprising a polymeric material and the block
copolymer according to claim 1.
5. The polymer composition according to claim 4, wherein the amount of the
block copolymer added is 0.01 to 30 parts by weight based on 100 parts by
weight of the polymeric material.
6. A process for producing the block copolymer according to claim 1,
comprising the steps of:
a first step of polymerizing either a monomer for forming the M.sup.1 block
or a monomer for forming the M.sup.2 block in the presence of a
sulfur-containing compound having formula (XIII):
##STR61##
wherein R.sup.1 represents a hydrocarbon group having 1 to 10 carbon
atoms; R.sup.2 represents a hydrogen atom or a hydrocarbon group having 1
to 10 carbon atoms; R.sup.3 represents a benzyl group,
##STR62##
wherein R.sup.4 represents an alkyl group having 1 to 18 carbon atoms or
an alkyl group having 1 to 18 carbon atoms; so as to synthesize a polymer
initiator having a dithiocarbamate group as indicated in formula (XIII) at
the polymer terminal end; and
a second step of polymerizing the other monomer in the presence of the
polymer initiator obtained in the first step; wherein the polymerization
reactions in the first step and in the second step are carried out upon
exposure to ultraviolet rays.
Description
BACKGROUND OF THE INVENTION
This invention relates to a hydrophilic group-containing AB-type block
copolymer having a hydrophilic group-containing polymer chain and a
polymer chain having affinity for a resin.
It has been already known that a block copolymer is useful for modifying
the surface or interface of a resin and making its effect persistent.
The hydrophilic group-containing AB-type block copolymer of the present
invention functions in such a manner that the hydrophilic group-containing
polymer chain is oriented to the surface or interface of the resin to be
modified, while the polymer chain having affinity for a resin is fixed to
the resin. Accordingly, it can be used in various fields in which
excellent properties possessed by hydrophilic groups such as water
absorption capacity, antistatic properties, electrical conductivity, stain
resistance, non-fogging, oil resistance, adhesiveness to metals, glass and
ceramics, and compatibility with organisms are desired to be imparted to a
resin. Specifically, it can be used for a paint additive, resin additive,
surfactant, anti-foaming agent, flocculating agent, dispersant, builder,
scale retarder, toner, adhesive, fibers, membrane, sealant, rubber,
binder, water-absorptive resin, etc.
An attempt has heretofore been made to synthesize hydrophilic
group-containing block copolymers which are expected to have the above
mentioned excellent surface or interface modification effect, but has not
been successful with radical polymerization methods. Meanwhile, Japanese
Laid-Open Patent Publication No. 202261/84 has proposed that a hydrophilic
group-containing block copolymer can be synthesized by use of a polymeric
peroxide or a polyazo compound.
However, when a hydrophilic group-containing block copolymer is synthesized
by the use of a polymeric peroxide or polyazo compound as mentioned above,
the molecular weight of the resulting polymer can be controlled with
difficulty and further homopolymers are by-produced whereby it is
difficult to obtain a block copolymer of high purity.
SUMMARY OF THE INVENTION
An object of the present invention is to solve the above problems. The
present inventor has found that a hydrophilic group-containing AB-type
copolymer having a hydrophilic group-containing polymer chain and a
polymer chain having affinity for a resin to be modified in combination
can impart various excellent properties possessed by hydrophilic groups
such as water absorption capacity, antistatic properties, electrical
conductivity, stain resistance, non-fogging, oil resistance, adhesiveness
to metals, glass and ceramics, and compatibility with organisms to the
surface or interface of a resin to be modified, and also the effects are
permanent, thereby accomplishing the present invention.
More specifically, the hydrophilic group-containing AB-type block copolymer
is represented by the following formula (I):
##STR4##
wherein R.sup.1 represents a hydrocarbon group having 1 to 10 carbon
atoms; R.sup.2 represents a hydrogen atom or a hydrocarbon group having 1
to 10 carbon atoms; R.sup.3 represents a benzyl group,
##STR5##
(wherein R.sup.4 represents an alkyl group having 1 to 18 carbon atoms) or
an alkyl group having 1 to 18 carbon atoms; M represents a group
represented by the formula (M.sup.2).sub.m -(M.sup.1).sub.n or
(M.sup.1).sub.m -(M.sup.2).sub.n, each of m and n being a natural number
of 20 to 5,000: M.sup.1 represents a (meth)acrylate residue represented by
the formula:
##STR6##
(wherein R.sup.5 represents a hydrogen atom or a methyl group, and R.sup.6
represents a hydrocarbon group having 1 to 18 carbon atoms) or an aromatic
vinyl residue represented by the formula:
##STR7##
(wherein R.sup.7 represents a hydrogen atom or a methyl group, R.sup.8
represents a phenyl group, a halogenated phenyl group or an alkylphenyl
group) or a fatty acid vinyl ester residue represented by the formula:
##STR8##
(wherein R.sup.9 represents a hydrocarbon group having 1 to 18 carbon
atoms); M.sup.2 represents a hydrophilic group-containing vinyl residue
represented by any one of the formulae (II) to (XII):
##STR9##
wherein R.sup.10, R.sup.11 each represent a hydrogen atom, a methyl or a
hydroxyl group, and Z represents a hydrogen atom, an alkali metal atom,
ammonium or an organic amine;
##STR10##
wherein R.sup.10 and Z have the same meanings as in the formula (II), and
R.sup.12 represents an alkylene group having 1 to 10 carbon atoms;
##STR11##
wherein R.sup.10, R.sup.11 and Z have the same meanings as in the formula
(II), and R.sup.12 has the same meaning as in the formula (III);
##STR12##
wherein R.sup.10 and R.sup.11 have the same meanings as in the formula
(II), R.sup.13 and R.sup.14 each represent a hydrogen atom, an alkyl group
having 1 to 10 carbon atoms or a sulfonated alkyl group represented by the
formula--R.sup.12 SO.sub.3 Z (wherein R.sup.12 and Z have the same
meanings as in the formula (III));
##STR13##
wherein R.sup.10, R.sup.11 and R.sup.12 have the same meanings as in the
formula (IV), and R.sup.13 and R.sup.14 have the same meanings as in the
formula (V);
##STR14##
wherein R.sup.10, R.sup.11, R.sup.12, R.sup.13 and R.sup.14 have the same
meanings as in the formula (VI), and R.sup.15 represents a hydrogen atom,
an alkyl group having 1 to 10 carbon atoms or a sulfonated alkyl group
represented by the formula--R.sup.12 SO.sub.3 Z (wherein R.sup.12 and Z
have the same meanings as in the formula (III));
##STR15##
wherein R.sup.16 represents a hydroxylated alkyl group having 1 to 18
carbon atoms and having at least one hydroxyl group, and R.sup.10 and
R.sup.11 have the same meanings as in the formula (II);
##STR16##
wherein R.sup.10 and R.sup.11 have the same meanings as in the formula
(II), and R.sup.17 represents a polyethylene glycol group or a
polypropylene glycol group represented by the formula
##STR17##
(wherein l represents a natural number of 1 to 10 and X represents a an
alkyl group having 1 to 10 carbon atoms or Z, --PO.sub.3 H.sub.2,
--PO.sub.3 HZ or --PO.sub.3 Z.sub.2 (wherein Z has the same meaning as in
the formula (II));
##STR18##
wherein R.sup.10 and Z have the same meanings as in the formula (II);
##STR19##
wherein R.sup.10 has the same meaning as in the formula (II); or
##STR20##
wherein R.sup.10, R.sup.11 and Z have the same meanings as in the formula
(II); and M.sup.2 further represents a vinylpyrrolidone residue or an
ammonium salt of the formula (V), (VI) or (VII).
DETAILED DESCRIPTION OF THE INVENTION
The residue contained in the formula (I) herein means recurring units of a
monomer having vinyl group which have been bonded by addition
polymerization.
The hydrophilic group-containing AB-type block coploymer according to the
present invention has a structure that a hydrophilic group containing
polymer chain and a polymer chain having affinity for a resin to be
modified are chemically bonded in a straight chain.
When a composition is formed by compounding such AB block copolymer with a
resin to be modified by means of, for example, melt kneading, it will take
a morphology in which the free energy of such composition system as a
whole becomes the minimum and therefore the hydrophilic group-containing
polymer chain will be orientated to the surface or interface of the resin,
while the resin-affinitive polymer chain will play a role to fix the
polymer firmly on the resin. Accordingly, the AB-type block copolyemr
modifies the surface or interface of the resin, and also easy bleed-out or
easy peel-off of such AB-type block copolymer itself from the resin can be
prevented.
Therefore, the hydrophilic group-containing AB-type block copolymer of the
present invention can impart various properties inherent in hydrophilic
group atoms onto the surface or interface of a resin, and also give
permanency to such properties.
Monomers for forming the resin-affinitive polymer chain
The M.sup.1 which forms the resin-affinitive polymer chain is a
(meth)acrylic acid ester residue represented by the formula:
##STR21##
(wherein R.sup.5 represents hydrogen atom or a methyl group, and R.sup.6
represents a hydrocarbon group having 1 to 18 carbon atoms).
Examples of monomers forming the (meth)acrylic acid ester residue may
include (meth)acrylates such as methyl (meth)acrylate, ethyl
(meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl
(meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate,
isononyl (meth)acrylate, decyl (meth)acrylate, stearyl (meth)acrylate, and
the like.
Alternatively, M.sup.1 represents an aromatic vinyl residue represented by
the formula:
##STR22##
(wherein R.sup.7 represents hydrogen atom or methyl group, and R.sup.8
represents a phenyl group, a halogenated phenyl group or an alkylphenyl
group).
Examples of the monomers for forming the aromatic vinyl residue may include
styrene, p-methylstyrene, o-methylstyrene, .alpha.-methylstyrene,
.beta.-methylstyrene p-chloromethylstyrene, p-bromomethylstyrene and the
like.
Alternatively, M.sup.1 represents an aliphatic vinyl ester residue
represented by the formula:
##STR23##
(wherein R.sup.9 represents a hydrocarbon group having to 18 carbon
atoms).
Examples of monomers for forming the aliphatic vinyl ester residue may
include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate,
vinyl 2-ethylhexanoate, vinyl laurate, vinyl stearate, etc.
Monomers for forming the hydrophilic group-containing polymer chain
M.sup.2 represents a hydrophilic group-containing vinyl residue represented
by any one of the formulae (II) to (XII):
##STR24##
wherein R.sup.10 and R.sup.11 each represent a hydrogen atom, a methyl or
hydroxyl group, and Z represents a hydrogen atom, an alkali metal,
ammonium or an organic amine.
Examples of monomers for forming the hydrophilic group-containing vinyl
residue of the formula (II) may include (meth)acrylic acid, crotonic acid,
sodium (meth)acrylate, potassium crotonate, ammonium (meth)acrylate,
##STR25##
wherein R.sup.10 and Z have the same meanings as in the formula (II), and
R.sup.12 represents an alkylene group having 1 to 10 carbon atoms.
Examples of monomers for forming the hydrophilic group-containing vinyl
residue of the formula (III) include itaconic acid, sodium itaconate,
ammonium itaconate,
##STR26##
wherein R.sup.10, R.sup.11 and Z have the same meanings as in the formula
(II), and R.sup.12 has the same meaning as in the formula (III).
Examples of monomers for forming the hydrophilic group-containing vinyl
residue of the formula (IV) may include:
##STR27##
wherein R.sup.10 and R.sup.11 have the same meanings as in the formula
(II), R.sup.13 and R.sup.14 each represent a hydrogen atom, an alkyl group
having 1 to 10 carbon atoms or a sulfonated alkyl group represented by the
formula--R.sup.12 SO.sub.3 Z (wherein R.sup.12 and Z have the same
meanings as in the formula (III)).
Examples of monomers for forming the hydrophilic group-containing vinyl
residue of the formula (V) may include (meth)acrylamide,
N,N-dimethyl(meth)acrylamide,
##STR28##
wherein R.sup.10, R.sup.11 and R.sup.12 have the same meanings as in the
formula (IV), and R.sup.13 and R.sup.14 have the same meanings as in the
formula (V).
Examples of monomers for forming the hydrophilic group-containing vinyl
residue of the formula (VI) may include:
##STR29##
wherein R.sup.10, R.sup.11, R.sup.12, R.sup.13 and R.sup.14 have the same
meanings as in the formula (VI), and R.sup.15 represents a hydrogen atom,
an alkyl group having 1 to 10 carbon atoms or a sulfonated alkyl group
represented by the formula--R.sup.12 SO.sub.3 Z (wherein R.sup.12 and Z
have the same meanings as in the formula (III)). Examples of monomers for
forming the hydrophilic group-containing vinyl residue of the formula
(VII) may include:
##STR30##
wherein R.sup.16 represents a hydroxylated alkyl group having 1 to 18
carbon atoms and having at least one hydroxyl group, and R.sup.10 and
R.sup.11 have the same meanings as in the formula (II).
Examples of monomers for forming the hydrophilic group-containing vinyl
residue of the formula (VIII) may include 2-hydroxyethyl acrylate,
2-hydroxyethyl methacrylate,
##STR31##
wherein R.sup.10 and R.sup.11 have the same meanings as in the formula
(II), and R.sup.17 represents a polyethylene glycol group or a
polypropylene glycol group represented by the formula
##STR32##
(wherein l represents a natural number of 1 to 10 and X represents an
alkyl group having 1 to 10 carbon atoms or Z, --PO.sub.3 H.sub.2,
--PO.sub.3 HZ or --PO.sub.3 Z.sub.2 (wherein Z has the same meaning as in
the formula (I) and (II)).
Examples of monomers for forming the hydrophilic group-containing vinyl
risidue of the formula (IX) may include:
##STR33##
wherein R.sup.10 and Z have the same meanings as in the formula (II).
Examples of monomers for forming the hydrophilic group-containing vinyl
residue of the formula (X) may include:
##STR34##
wherein R.sup.10 has the same meaning as in the formula (II).
Examples of monomers for forming the hydrophilic group-containing vinyl
residue of the formula (XI) may include: wherein R.sup.10, R.sup.11 and Z
have the same meanings as in the formula (II).
##STR35##
Examples of monomers for forming the hydrophilic group-containing vinyl
residue of the formula (XII) may include:
##STR36##
M.sup.2 further represents a vinylpyrrolidone residue or an ammonium salt
of the formula (V), (VI) or (VII). An example of monomers for forming the
vinylpyrrolidone residue is vinylpyrrolidone, and examples of monomers for
forming the ammonium salt of the formula (V) may include:
##STR37##
Examples of monomers for forming the ammonium salt of the formula (VI) may
include:
##STR38##
Examples of monomers for forming the ammonium salt of the formula (VII) may
include:
##STR39##
Specific examples of hydrophilic group-containing monomers for forming the
hydrophilic group-containing polymer are as mentioned above, and at least
one of these is used as a main component of the hydrophilic
group-containing vinyl polymer. Other hydrophilic group-containing vinyl
monomers, vinyl monomers and crosslinking agents than the above main
component may also be used insofar as the modification effect of the block
copolymer on the surface or interface of a polymer material is to be
exhibited.
Preparation of block copolymer
The block copolymer of the present invention is produced by block
copolymerization, as follows.
According to a typical method, one of the monomer M.sup.1 for forming the
resin-affinitive polymer chain and the monomer M.sup.2 for forming the
hydrophilic group-containing polymer chain is polymerized by the action of
a radical polymerization initiator to form a polymer chain corresponding
to the resin-affinitive polymer chain or the hydrophilic group-containing
polymer chain and having at the terminal end a free radical source
comprising a free radical or a precursor thereof (first step) and then
polymerizing the other monomer with the free radical source (second step).
The radical polymerization initiator in this case should preferably have
the functions of chain transfer and termination in combination. A specific
example of such radical polymerization initiator is one which gives
dithiocarbamate group to the terminal end of the polymer chain formed. The
dithiocarbamate group formed at the terminal end of one block polymer
chain is decomposed by giving light energy thereto to generate free
radical, wherefrom formation of the other block is initiated.
The initiator preferably used in synthesis of the block copolymer according
to the present invention, which has the functions of chain transfer and
termination in combination in a radical polymerization process as set
forth above, is called iniferter (Otsu, Kobunshi, 3, 222 (1984)).
Specifically, it is a sulfur-containing compound and a typical example
thereof is represented by the following formula (XIII). The block
copolymer can be synthesized by the use of one or more kinds of the
compounds.
##STR40##
(wherein R.sup.18 represents a hydrocarbon group having 1 to 10 carbon
atoms, R.sup.19 represents a hydrogen atom or a hydrocarbon group having 1
to 10 carbon atoms, and R.sup.20 represents a benzyl group,
##STR41##
(wherein R.sup.21 represents an alkyl group having 1 to 18 carbon atoms)
or an alkyl group having 1 to 18 carbon atoms).
The hydrogen atom in R.sup.20 may be substituted with a halogen, hydroxyl
group, an alkoxyl group or carboxylic acid group, etc., unless the
substitution remarkably changes the electronic state of the compound or
remarkably increases the steric hindrance thereby lowering the ability of
the compound as a radical polymerization initiator.
The compounds represented by the above formula can be synthesized with good
yield from corresponding halides and dithiocarbamic acid salts. For
example, N,N-diethylbenzyldithiocarbamate can be synthesized from benzyl
bromide and sodium N,N-diethyldithiocarbamate.
In order for the compounds to function as the initiator through
decomposition of themselves, to initiate the first step and the second
step of block copolymerization, can be employed a UV-ray of wavelengths of
300 to 500 nm.
Copolymerization
As mentioned above, the block copolymer according to the present invention
can be synthesized according to the following two steps.
First step: A. first vinyl monomer is polymerized by the use of the above
mentioned sulfur type radical polymerization initiator to synthesize a
polymer initiator having a dithiocarbamate group at the polymer terminal
end.
Second step: By the use of the polymer initiator synthesized in the first
step, a second vinyl monomer is polymerized to form a block copolymer.
Here, the dithiocarbamate at the polymer terminal end is decomposed to
become a radical initiation site (as described in detail below).
In such two steps, the hydrophilic group-containing vinyl monomer can be
used as the first monomer and the resin-affinitive vinyl monomer as the
second monomer. Alternatively, the resin-affinitive vinyl monomer can be
used as the first monomer and the hydrophilic group-containing vinyl
monomer as the second monomer.
In the case of conducting photopolymerization through the first step and
the second step, the polymerization system should be preferably maintained
at a temperature of 150.degree. C. or lower from the standpoint of
protection of dithiocarbamate group.
When photopolymerization is employed in these steps, the polymerization
system may be either homogeneous or heterogeneous, provided that
sufficient light energy for dissociation can be transmitted to the
initiation site. Usually, however, bulk polymerization or solution
polymerization is used in the first step, while in the second step
solution polymerization or polymerization in a solution having the polymer
initiator dissolved in the second monomer is used.
A preferred solvent to be used for solution polymerization is one which has
no characteristic absorption for UV-rays of a wavelength of 300-500 nm,
has a small chain transfer constant and dissolves well the monomers and
the polymers. Examples of such solvents include benzene, toluene, xylene,
ethylbenzene, acetone, methyl ethyl ketone, ethyl acetate,
dimethylformamide, isopropyl alcohol, butanol, hexane and heptane.
The average degree of polymerization or the molecular weight of each
component of the block copolymer can be controlled by the molar ratio of
the initiator to the monomer. For example, when 1 mol% of benzyl
N,N-diethyldithiocarbamate is added to methyl methacrylate with a
molecular weight as a monomer of 100, the number average molecular weight
will be about 10,000 and the weight average molecular weight about 20,000.
In the case of 0.1 mol%, they will be about 100,000 and about 200,000,
respectively.
Similarly, in the second step, the molecular weight can be controlled by
the molar ratio of the polymer initiator to the second monomer.
For a suitable block copolymer, the average degree of polymerization should
be in the range of 20 to 5,000 with the hydrophilic group-containing
polymer chain, 20 to 5,000 with the resin-affinitive polymer chain, and 40
to 10,000 with the block copolymer as a whole. If the average degree of
polymerization of the hydrophilic group-containing polymer chain is less
than 20, the block copolymer cannot sufficiently cover the surface or
interface of a polymer material, whereby the effect of modifying the
material will be insufficient. If it is over 5,000, on the other hand, the
diffusion speed of the block copolymer is small, whereby it does not
adequately migrate onto the surface or interface of a polymeric material
thereby producing a poor effect of modification.
If the average degree of polymerization of the resin-affinitive
polymerization chain is less than 20, the block copolymer has a low
affinity for a polymeric material and thus is not fixed stably onto the
material, leading to poor dispersion and easy bleeding out of the block
copolymer. If it is over 5,000, the block copolymer does not migrate well
onto the surface or interface of a polymeric material due to a small
diffusion speed of the block copolymer, whereby the effect of modification
will be insufficient.
Dithiocarbamate groups on both the ends of the block copolymer produced can
be made inactive to the ultraviolet by a post treatment. The block
copolymer may be made inactive to ultraviolet by, for example, heat
treating the block copolymer for several minutes at a temperature of
250.degree. C. or higher or by treating the block copolymer with acidic or
alkaline solution. Alternatively, the carbamate terminals of the block
copolymer can be substituted by UV-insensitive groups by, for example,
adding under irradiation of the ultraviolet a chemical which has a large
chain transfer constant such as a thiol compound.
Modification of surface characteristics
Modification of surface characteristics according to the present invention
may be effected by compounding the specific block copolymer with a
polymeric material. As a method for compounding, there may be employed a
method in which a solution or dispersion of the specific block copolymer
in a solvent is applied on the surface of a polymeric material, a method
in which the block copolymer is compounded with a polymeric material
during molding of the material, a method in which a film is formed after
dissolving a polymeric material and the block copolymer in a solvent, a
method in which the block polymer is formed into a sheet and pressurized
under heating or adhered with an adhesive onto the surface of a polymeric
material surface, or a method in which the block copolymer in the form of
powder is attached by melting onto the surface of a polymeric material.
Among such methods, preferred ones are those in which the block copolymer
and the objective polymeric material are combined via their dissolved or
melted state.
The amount of the block copolymer to be compounded may be 0.01 to 30 parts
by weight, preferably 0.1 to 10 parts by weight, based on 100 parts by
weight of a polymeric material. If the amount is less than 0.01 part by
weight, the effect according to present invention will be insufficient,
while characteristics inherent in a polymeric material may be deteriorated
if it is in excess of 30 parts by weight.
EXAMPLES
The following examples are to illustrate some embodiments of the present
invention without implying a limitation.
All parts and % in the examples are based on weight.
Preparation of block copolymer
PREPARATION 1
(First Step)
In a thermostat tank with an inner temperature of 50.degree. C., a vessel
made of Pyrex glass with a diameter of 3 cm and a volume of 300 ml was
placed at a distance of 10 cm from a UV-ray lamp of an output of 400W (H
400L, produced by TOSHIBA CO.), and 100 g of styrene and 2.39 g of
benzyl-N,N-diethyldithiocarbamate were charged into the vessel. After the
vessel was replaced with nitrogen, it was sealed and photopolymerization
was carried out under UV-ray irradiation by the above UV-ray lamp for 10
hours.
The polymer obtained was a pale yellow transparent solid, with the residual
monomer amount being 1.6%. The number average molecular weight calculated
on polystyrene (hereinafter abbreviated as "Mn") measured by gel
permeation chromatography (GPC) was found to be 9,800, and the weight
average molecular weight calculated on polystyrene (hereinafter
abbreviated as "Mw") 22,000. This polymer is a polymeric initiator.
(Second Step)
A solution obtained by well mixing 40 g of powder obtained by pulverizing
the polymer obtained in the first step, 40 g of 2-hydroxyethyl
methacrylate and 160 g of methyl ethyl ketone was charged into the same
vessel in the same device as used in the first step. After replacing the
inside of the vessel with nitrogen, photopolymerization was carried out
under UV-ray irradiation for 10 hours to obtain a translucent white
polymer dispersion.
The polymer dispersion was subjected to reprecipitation with hexane
followed by drying to obtain a block copolymer. The block copolymer was
found to have Mn of 22,000 and Mw of 45,000 as measured by GPC, with the
total amount of residual monomer being less than 1%. The percentage of
block formation measured by solvent extraction was 86%.
PREPARATION 2
(First Step)
100 g of methyl methacrylate and 2.39 g of
benzyl-N,N-diethyldithiocarbamate were charged into the same vessel in the
same device as in Preparation 1, and photopolymerization was carried out
in the same way as in Preparation 1. The polymer obtained was a pale
yellow transparent solid, with the residual monomer amount being 1.0%. The
polymer had Mn of 9,900 and Mw of 23,000.
(Second Step)
Except for using 40 g of the pulverized powder of the polymer obtained in
the first step, 40 g of 2-hydroxyethyl methacrylate and 160 g of methyl
ethyl ketone, photopolymerization and post-treatment were carried out in
the same manner as in Preparation 1 to obtain a block copolymer. The
copolymer was found to have Mn of 23,000 and Mw of 48,000, with the total
amount of residual monomers being less than 1%. The percentage of block
formation measured by solvent extraction was 82%.
PREPARATION 3
Except for using 40 g of the pulverized powder of the polymer obtained in
the first step of Preparation 2, 40 g of acrylic acid and 160 g of methyl
ethyl ketone, photopolymerization and post-treatment were carried out in
the same manner as in the second step of Preparation 1 to obtain a block
copolymer. The copolymer was found to have Mn of 22,000 and Mw of 46,000,
with the total amount of residual monomers being less than 1%. The
percentage of block formation measured by solvent extraction was 84%.
PREPARATION 4
Except for using 40 g of the pulverized powder of the polymer obtained in
the first step of Preparation 2, 40 g of sodium styrenesulfonate, 80 g of
methanol and 80 g of acetone, photopolymerization and post-treatment were
carried out in the same manner as in the second step of Preparation 1 to
obtain a block copolymer. The copolymer was found to have Mn of 21,000 and
Mw of 46,000, with the total amount of residual monomers being less than
1%. The percentage of block formation measured by solvent extraction was
78%.
PREPARATION 5
(First Step)
Except for using 100 g of methyl methacrylate and 2.47 g of ethyl
2-N,N-diethyldithiocarbamylisobutyrate, photopolymerization and
post-treatment were carried out in the same manner as in the first step of
Preparation 1 to obtain a polymer with Mn of 9,800 and Mw of 22,000.
(Second Step)
Except for using 40 g of the pulverized powder of the polymer obtained in
the first step, 40 g of 2-hydroxyethyl methacrylate and 160 g of methyl
ethyl ketone, photopolymerization and post-treatment were carried out in
the same manner as in the second step of Preparation 1 to obtain a block
copolymer. The copolymer was found to have Mn of 23,000 and Mw of 49,000,
with the total amount of residual monomers being less than 1%. The
percentage of block formation measured by solvent extraction was 80%.
EXAMPLE 1
100 parts of polystyrene resin powder and 5 parts of the block copolymer
obtained in Preparation 1 were kneaded by an extruder to form a sheet, and
further press molded to obtain a sheet with a thickness of 0.5 mm.
The sheet was not colored, with no bleeding out onto the surface, and was
good in processability.
For this sheet and a sheet formed similarly from the polystyrene resin
alone as a comparative testing sample their surface resistance values and
contact angles with pure water were measured (measurement conditions:
relative humidity: 30%, temperature: 20.degree. C.). The results are shown
in Table 1.
Note (The same holds in the following Tables):
TABLE 1
______________________________________
Resin Surface resistance*.sup.1)
Contact angle*.sup.2)
______________________________________
Polystyrene resin
3 .times. 10.sup.5 .OMEGA..sup.
50.degree.
blended with block
copolymer
Polystyrene resin
5 .times. 10.sup.13 .OMEGA.
95.degree.
______________________________________
*.sup.1) measured by means of a surface resistance measuring instrument
produced by Sanko Seiki K.K.
*.sup.2) measured by means of a FACE contact angle needle (Model CAD)
produced by Kyowa Kaimen Kaguku, K.K.
As is apparent from Table 1, the sheet formed from polystyrene blended with
the block copolymer has remarkably low surface resistance value and
contact angle as compared with the sheet formed from the resin blended
with no block copolymer showing clearly the surface modifying effect of
the block copolymer.
Next, the surface of the sheet formed from the resin blended with the block
copolymer was washed with tap water of 25.degree. C. at a flow rate of 2
liter/min. for one hour, and then the same measurements were made to give
entirely the same results with those before water washing.
EXAMPLE 2
100 Parts of polyvinyl acetate resin powder and 5 parts of the block
copolymer obtained in Preparation 2 were processed in the same manner as
in Example 1 to form a sheet. The sheet obtained was not colored, without
bleeding and was also good in processability. The sheet and a sheet formed
similarly from the polyvinyl acetate resin alone were subjected to the
same measurement as in Example 1 to give the results as shown in Table 2.
TABLE 2
______________________________________
Resin Surface resistance
Contact angle
______________________________________
Polyvinyl acetate resin
6 .times. 10.sup.6 .OMEGA..sup.
40.degree.
blended with block
copolymer
Polyvinyl acetate resin
5 .times. 10.sup.15 .OMEGA.
80.degree.
______________________________________
As is apparent from Table 2, the surface characteristics of the resin were
remarkably modified by the addition of the block copolymer. When the same
measurements were made on the sheet formed from the resin blended with the
block copolymer after washing the sheet with water in the same manner as
in Example 1, the results were found to be the same with those before
water washing.
EXAMPLE 3
100 Parts of polyvinyl chloride resin powder and 5 parts of the block
copolymer obtained in Preparation 2 were formed into a sheet in the same
manner as in Example 1. The sheet obtained was not colored, without
bleeding and was good in processability. The characteristics' values
measured in the same manner as in Example 1 are as shown in Table 3.
TABLE 3
______________________________________
Resin Surface resistance
Contact angle
______________________________________
Polyvinyl chloride resin
2 .times. 10.sup.5 .OMEGA..sup.
45.degree.
blended with block
copolymer
Polyvinyl chloride resin
5 .times. 10.sup.16 .OMEGA.
81.degree.
______________________________________
As is apparent from Table 3, the surface characteristics of the resin were
remarkably modified by the addition of the block copolymer. When the same
measurements were made on the sheet formed from the resin blended with the
block copolymer after washing the sheet with water in the same manner as
in Example 1, the results were found to be the same with those before
water washing.
EXAMPLE 4
A sheet was prepared according to the procedure of Example 1 except for
using 100 parts of polyvinylidene fluoride resin powder and 5 parts of the
block copolymer obtained in Preparation 2. The sheet obtained was not
colored, without bleeding and was good in processability. The
characteristics' values measured in the same manner as in Example 1 are as
shown in Table 4.
TABLE 4
______________________________________
Resin Surface resistance
Contact angle
______________________________________
Polyvinylidene fluoride
3 .times. 10.sup.6 .OMEGA..sup.
60.degree.
resin blended with block
copolymer
Polyvinylidene fluoride
5 .times. 10.sup.16 .OMEGA.
105.degree.
resin
______________________________________
As is apparent from Table 4, the surface characteristics of the resin were
remarkably modified by the addition of the block copolymer. When the same
measurements were made on the sheet formed from the resin blended with the
block copolymer after washing the sheet with water in the same manner as
in Example 1, the results were found to be the same with those before
water washing.
EXAMPLE 5
A sheet with a thickness of 1 mm was obtained in the same manner as in
Example 1 except for using 100 parts of polyisoprene rubber and 5 parts of
the block copolymer obtained in Preparation 2. The sheet was not colored,
without bleeding and good in processability. For this sheet and a sheet
formed from the resin blended with no block copolymer, surface resistance
values and surface resistivity values after friction were measured to give
the results as shown in Table 5.
TABLE 5
______________________________________
Surface resistance
Resin Surface resistance
after rubbing*.sup.1)
______________________________________
Polyisoprene rubber
6 .times. 10.sup.6 .OMEGA..sup.
6 .times. 10.sup.6 .OMEGA..sup.
blended with block
copolymer
Polyisoprene rubber
3 .times. 10.sup.14 .OMEGA.
5 .times. 10.sup.16 .OMEGA.
______________________________________
Note
(The same holds in Table 6):
*.sup.1) measured after rubbing the sheet with a cotton cloth for 3
minutes using Rotary Static Tester (produced by Koashokai K.K., rotating
speed:150 rpm) under the same environmental conditions as in Example 1.
As is apparent from Table 5, the sheet formed from the resin blended with
the block copolymer has a low surface resistance value and the value is
not changed after rubbing. In contrast, the sheet formed from the resin
blended with no block copolymer has a high resistance value, and the value
rises further higher after rubbing. When the same measurements were made
on the sheet formed from the resin blended with the block copolymer after
washing the sheet with water in the same manner as in Example 1, the
results were found to be the same with those before water washing.
EXAMPLE 6
100 Parts of polymethyl methacrylate resin and 5 parts of the block
copolymer obtained in Preparation 2 were dissolved in ethyl acetate, and a
film was prepared according to the solvent film formation method. The film
obtained was not colored, with no bleeding.
For this film, and a film formed in the same manner except for not using
the block copolymer at all, surface resistivity values and surface
resistance values after rubbing were measured. The results are as shown in
Table 6.
TABLE 6
______________________________________
Surface resistance
Resin Surface resistance
after rubbing
______________________________________
Polymethyl methacrylate
7 .times. 10.sup.6 .OMEGA..sup.
7 .times. 10.sup.6 .OMEGA..sup.
resin blended with block
copolymer
Polymethyl methacrylate
5 .times. 10.sup.15 .OMEGA.
5 .times. 10.sup.16 .OMEGA.
resin
______________________________________
As regards the film prepared with addition of the block copolymer, the
surface resistance value is not changed after rubbing, thus exhibiting
very good antistatic effect. When the same measurements were made on the
film after washing the film with water in the same manner as in Example 1,
the results were found to be the same with those before water washing.
EXAMPLE 7
A dispersion of 30 parts of the block copolymer obtained in Preparation 2
in 100 parts of ethyl acetate was coated on an acrylic resin plate by
means of bar coating so that the thickness of the coating after drying
would be 8 .mu., and dried at room temperature for 2 hours and further at
60.degree. C. for 2 hours. The surface resistance value and the contact
angle with pure water of the resulting acrylic resin plate were measured
under the same conditions as in Example 1. The results are as shown in
Table 7.
TABLE 7
______________________________________
Resin Surface resistance
Contact angle
______________________________________
Acrylic resin plate coated
8 .times. 10.sup.6 .OMEGA..sup.
45.degree.
with block copolymer
Acrylic resin plate
5 .times. 10.sup.16 .OMEGA.
80.degree.
______________________________________
As is apparent from Table 7, the resin plate coated with the block
copolymer has a remarkably low surface resistance value and contact angle
as compared with the plate not coated with the block copolymer. When the
same measurements were made on the plates coated with the block copolymer
after washing the plate with water in the same manner as in Example 1, the
results were found to be the same with those before washing.
EXAMPLE 8
A mixture of 100 parts of an acrylic resin varnish for paint (solution in
ethyl acetate with solid content of 30%) with 2 parts of the block
copolymer obtained in Preparation 2, which mixture had a viscosity of 19
to 20 sec. as measured by Ford cup No.4, was spray coated onto a
polymethyl methacrylate resin sheet previously washed with ethanol, and
dried at 60.degree. C. for one hour. For the coated sheet obtained and the
sheet similarly coated with the acrylic resin varnish not blended with the
block copolymer, the same measurements as in Example 1 were conducted to
obtain the results as shown in Table 8.
TABLE 8
______________________________________
Resin Surface resistance
Contact angle
______________________________________
Polymethyl methacrylate
3 .times. 10.sup.6 .OMEGA..sup.
45.degree.
resin sheet coated with
varnish blended with block
copolymer
Polymethyl methacrylate
5 .times. 10.sup.16 .OMEGA.
82.degree.
resin sheet coated with
varnish
______________________________________
As is apparent from the results in Table 8, the resin sheet coated with the
varnish blended with the block copolymer has both remarkably low surface
resistance value and contact angle as compared with the sheet coated with
the varnish blended with no block copolymer. When the same measurements
were made on the sheet coated with the varnish blended with the block
copolymer after washing the coated sheet with water in the same manner as
in Example 1, the results were found to be the same with those before
washing.
EXAMPLE 9
A sheet was prepared in the same manner as in Example 1, except for using
100 parts of polymethyl methacrylate resin and 5 parts of the block
copolymer obtained in Preparation 4, and its surface characteristics were
measured similarly as in Example 1. The results are as shown in Table 9.
The sheet obtained was not colored, without bleeding, and was good in
processability.
TABLE 9
______________________________________
Resin Surface resistance
Contact angle
______________________________________
Polymethyl methacrylate
6 .times. 10.sup.6 .OMEGA..sup.
56.degree.
resin blended with block
copolymer
Polymethyl methacrylate
5 .times. 10.sup.15 .OMEGA.
80.degree.
resin
______________________________________
As is apparent from the results in Table 9, the sheet formed from the resin
blended with the block copolymer has both remarkably low surface
resistance value and contact angle as compared with the sheet prepared
with addition of no block copolymer. When the same measurements were made
on the sheet formed from the resin blended with the block copolymer after
washing the sheet with water in the same manner as in Example 1, the
results were found to be the same with those before water washing.
EXAMPLE 10
A sheet was prepared in the same manner as in Example 1, except for using
100 parts of methyl methacrylate resin and the block copolymer obtained in
Preparation 4, and its surface characteristics were measured similarly as
in Example 1. The results are as shown in Table 10. The sheet obtained was
not colored, without bleeding, and was good in processability.
TABLE 10
______________________________________
Resin Surface resistance
Contact angle
______________________________________
Methyl methacrylate resin
3 .times. 10.sup.5 .OMEGA..sup.
45.degree.
blended with block
copolymer
Methyl methacrylate resin
5 .times. 10.sup.15 .OMEGA.
80.degree.
______________________________________
As is apparent from Table 10, the sheet formed from the resin blended with
the block copolymer has both remarkably low surface resistance value and
contact angle as compared with the sheet prepared with addition of no
block copolymer. When the same measurements were made on the sheet formed
from the resin blended with the block copolymer after washing the sheet
with water in the same manner as in Example 1, the results were found to
be the same with those before water washing.
EXAMPLE 11
A sheet was prepared in the same manner as in Example 1, except for using
100 parts of polymethyl methacrylate resin and the block copolymer
obtained in Preparation 5. The sheet obtained was not colored, without
bleeding, and was good in processability. The surface characteristics of
the sheet were measured similarly as in Example 1. The results are as
shown in Table 11.
TABLE 11
______________________________________
Resin Surface resistance
Contact angle
______________________________________
Polymethyl methacrylate
3 .times. 10.sup.6 .OMEGA.
40.degree.
resin blended with block
copolymer
Polymethyl methacrylate
15 .times. 10.sup.15 .OMEGA.
80.degree.
resin
______________________________________
As is apparent from Table 11, the sheet formed from the resin blended with
the block copolymer has both remarkably low surface resistivity value and
contact angle as compared with the sheet prepared with addition of no
block copolymer. When the same measurements were made on the sheet formed
from the resin blended with the block copolymer after washing the sheet
with water in the same manner as in Example 1, the results were found to
be the same with those before water washing.
EXAMPLE 12
A mixture of 100 parts of an acrylic resin varnish for paint (solution in
ethyl acetate with solid content of 30%) with 2 parts of the block
copolymer obtained in Preparation 3, which mixture had a viscosity of 19
to 20 sec. as measured by Ford cup No. 4, was spray coated on the various
plates shown in Table 13 previously washed with ethanol, and dried at
60.degree. C. for one hour. Also, the same varnish blended with no block
copolymer was similarly coated on the various substrates, followed by
drying. For the resulting coated plates, adhesiveness between the coatings
and the various base plates was evaluated. The results are as shown in
Table 12.
TABLE 12
______________________________________
Varnish coating
Varnish coating
blended with block
blended with no
Base plate copolymer block copolymer
______________________________________
Glass 100/100 0/100
aluminum 100/100 0/100
Copper 100/100 80/100
Tinplate 100/100 80/100
Zinc-plated steel
100/100 80/100
Stainless steel (SUS 304)
100/100 10/100
______________________________________
Note:
Test method: the checker cellophane tape peeloff test.
As is apparent from Table 12, the coatings of the acrylic resin blended
with the block copolymer exhibit remarkably enhanced adhesiveness to the
various base plates as compared with the coatings without addition of the
block copolymer, which clearly shows the surface (interface) modification
effect of the block copolymer. When the same adhesion test was conducted
after dipping the various plates coated with the varnish in tap water of
25.degree. C. for 24 hours, both of the coatings blended with the block
copolymer and blended with no block copolymer showed the same results with
those before water dipping.
Top